How to tell if jade is real (and which home tests to ignore)

The most searched question about jade isn't what it means or what it's worth. It's whether it's real. That makes sense. A lot of what gets sold as jade is dyed quartz, glass, resin or jade that has been bleached and filled with plastic.

Here's the honest version. No test you can do at the kitchen table proves that a piece is natural, untreated jade. Some home tests can rule out an obvious fake. Most of the popular ones can't even do that.

First, what "real" actually means

There are two separate questions, and most guides mix them up.

• Is it jade at all? Real jade is one of two minerals, jadeite or nephrite. Anything else is a different stone, however green it is.
• Has it been treated? A piece can be genuine jadeite and still have been bleached with acid, filled with polymer resin or dyed. The trade calls these B and C jade, and they're worth a fraction of untreated stone.

A test that answers the first question tells you nothing about the second. Keep that in mind as you read the rest.

The home tests that don't tell you much

"Real jade feels cold"

It does. So does glass, and so does almost every other stone. Stone pulls heat from your skin faster than plastic, so it feels cool and then slowly warms up. The cold test can catch a plastic bead. It can't separate jade from glass or dyed quartz.

The scratch test

Jade sits at about 6 to 7 on the hardness scale and a steel knife at about 5.5, so the theory is that a knife won't scratch real jade. True, but quartz is a 7, so a knife won't scratch dyed quartz either. You learn very little, and if you press hard on a softer stone you've damaged it. Skip this one.

The lighter test

The idea is that real jade won't blacken. In practice a flame can crack stone, burn off the wax polish most jade is finished with, and scorch a treated piece. It proves nothing you can't learn more safely another way.

Water drops, magnets and tapping

A drop of water beading on the surface tells you the stone is polished, not what it is. Jade isn't magnetic, but neither are glass, quartz or resin. Tapping a bangle and listening for a ring is an old trick that experienced traders use alongside other checks. On a chain with a metal clasp it means nothing.

The checks that do tell you something

Look through it with a torch

Shine a small torch through the stone. Natural jade shows an uneven, slightly fibrous or grainy texture inside, with soft cloudy patches. Glass often shows tiny round bubbles or swirls. Dyed stone tends to show the colour gathered along cracks, like ink that has run into fine lines. This is a good way to spot a cheap imitation. It won't catch a polymer-filled stone, which can look clean and bright.

Look at the colour across the piece

Natural jade varies. On a chain, one link might be a shade deeper than the next, or carry a little cloud or vein. A piece where every link is exactly the same bright colour, at a low price, deserves a second look.

Weigh it in water

This is the most reliable check you can do at home, and it only works on loose stones. Weigh the stone in air, then weigh it hanging in a cup of water. Divide the weight in air by the difference. Jadeite comes out around 3.33, nephrite around 2.95. Quartz is about 2.65 and serpentine, a common lookalike, is lower again. You need a scale that reads to 0.01 g, and the metal in a clasp throws the number off, so it's not practical for a finished chain.

UV light

Under a long-wave UV torch, polymer-filled jade often glows a chalky blue-white. Some natural jade fluoresces too, though, so treat a glow as a reason to ask questions, not as proof.

The check that settles it

A gemmologist can measure how the stone bends light with a refractometer, which separates jadeite from nephrite from the common imitations in a minute or two. To find out whether a stone has been filled with polymer, a gem lab uses infrared spectroscopy. Gems & Gemology, the GIA's journal, has described infrared as the only method that gives conclusive evidence of polymer in every case.

Many jewellers can do the basic identification for you. For a firm answer on treatment, ask them to refer you to a gem lab.

The honest answer to "how do I know it's real?" is: have someone qualified look at it. Everything else is a clue.

How we handle it

Every Luzari jade piece names its stone, whether that's nephrite, Guatemalan jade or Burmese jade, and every one is natural jade, never dyed, bleached or polymer-filled.

We don't expect you to take that on trust. You have 90 days from delivery to take your piece, unworn, to any jeweller or gemmologist you like. If it isn't what the listing says, send it back in its gift box and we'll refund you. The details are in our returns policy.

That's longer than most jade sellers give you, and it's on purpose. The stone should be able to stand up to a second opinion. Have a look at the full jade collection, or read what Type A, B and C jade mean if you want to know what a lab is looking for.